Structural and biophysical analysis of cytochrome P450 2C9*14 and *27 variants in complex with losartan.

The human cytochrome P450 (CYP) 1, 2 and 3 families of enzymes are responsible for the biotransformation of a majority of the currently available pharmaceutical drugs. The highly polymorphic CYP2C9 predominantly metabolizes many drugs including anticoagulant S-warfarin, anti-hypertensive losartan, anti-diabetic tolbutamide, analgesic ibuprofen, etc. There are >80 single nucleotide changes identified in CYP2C9, many of which significantly alter the clearance of important drugs. Here we report the structural and biophysical analysis of two polymorphic variants, CYP2C9*14 (Arg125His) and CYP2C9*27 (Arg150Leu) complexed with losartan. The X-ray crystal structures of the CYP2C9*14 and *27 illustrate the binding of two losartan molecules, one in the active site near heme and another on the periphery. Both losartan molecules are bound in an identical conformation to that observed in the previously solved CYP2C9 wild-type complex, however, the number of losartan differs from the wild-type structure, which showed binding of three molecules. Additionally, isothermal titration calorimetry experiments reveal a lower binding affinity of losartan with *14 and *27 variants when compared to the wild-type. Overall, the results provide new insights into the effects of these genetic polymorphisms and suggests a possible mechanism contributing to reduced metabolic activity in patients carrying these alleles.

Quality Evaluation of Gentamicin Sulfate Reference Standards in Japanese Pharmacopoeia Using Hydrophilic Interaction Chromatography Combined With Tandem Mass Spectrometry.

BACKGROUND: Through the recent development of analytical technology, antibiotics quantification in the Japanese Pharmacopoeia (JP) has changed from traditional microbiological assays to physicochemical methods with high specificity and precision. However, for several multicomponent antibiotics without typical UV absorption, potency cannot be directly determined using instrumental methods such as high-performance liquid chromatography; therefore, traditional microbiological assays are still used. Gentamicin sulfate (GmS), which consists of three major components, C1, C1a, and C2, is such a typical antibiotic, and its antimicrobial potency continues to be assayed using microbiological methods in JP monographs. Introduction of a physicochemical assay for GmS is needed to help ensure its quality and quantity. OBJECTIVE: This study aimed to develop quality control measures for GmS that could be complementary to quantitative assays and purity tests specified in the JP. METHODS: For each gentamicin C component (C1, C2, and C1a), theoretical potencies were determined based on the quantitative relationship between purity and potency, as measured by quantitative 1H NMR and microbiological assays, respectively. Two lots of the JP reference standard (RS) were used as test samples, with the contents of each component and impurity (sisomicin and garamine) being determined using hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). RESULTS: The ratios of theoretical potency for C1, C2, and C1a were 1.00, 1.21, and 1.80, respectively. The potencies of the GmS JP RSs, which were estimated based on the contents and theoretical potency of each C component, corresponded well with those determined through microbiological assays. Marked differences in impurities (%) between the two RS lots were highlighted by quantifying sisomicin and garamine. CONCLUSIONS: The developed analytical procedure enabled the characterization of two different JP RSs in terms of content ratio, potencies, and impurities. HIGHLIGHTS: Novel analytical procedures useful for routine quality control of GmS were developed using HILIC-MS/MS.

Impact of multiple H/D replacements on the physicochemical properties of flurbiprofen.

Although deuterium incorporation into pharmaceutical drugs is an attractive way to expand drug modalities, their physicochemical properties have not been sufficiently examined. This study focuses on examining the changes in physicochemical properties between flurbiprofen (FP) and flurbiprofen-d8 (FP-d8), which was successfully prepared by direct and multiple H/D exchange reactions at the eight aromatic C-H bonds of FP. Although the effect of deuterium incorporation was not observed between the crystal structures of FP and FP-d8, the melting point and heat of fusion of FP-d8 were lower than those of FP. Additionally, the solubility of FP-d8 increased by 2-fold compared to that of FP. Calculation of the interaction energy between FP/FP-d8 and water molecules using the multi-component density functional theory method resulted in increased solubility of FP-d8. These novel and valuable findings regarding the changes in physicochemical properties triggered by deuterium incorporation can contribute to the further development of deuterated drugs.

Validation of a genotyping technique for a surrogate marker of HLA-B∗58:01 for allopurinol-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in the Japanese population.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are rare but severe cutaneous adverse drug reactions. Certain human leukocyte antigen (HLA) types have been associated with SJS/TEN onset, e.g., HLA-B∗58:01 with allopurinol-induced SJS/TEN, but HLA typing is time-consuming and expensive; thus, it is not commonly used in clinical situations. In the previous work, we demonstrated that the single-nucleotide polymorphisms (SNP) rs9263726 was in absolute linkage disequilibrium with HLA-B∗58:01 in the Japanese population, and can be used as a surrogate marker for the HLA. Here, we developed a new genotyping method for the surrogate SNP using the single-stranded tag hybridization chromatographic printed-array strip (STH-PAS) technique and performed an analytical validation. The results of genotyping rs9263726 using STH-PAS correlated well with those obtained using the TaqMan SNP Genotyping Assay for 15 HLA-B∗58:01-positive and 13 HLA-B∗58:01-negative patients (analytical sensitivity and specificity were both 100%). Additionally, at least 1.11 ng of genomic DNA was sufficient to digitally and manually detect positive signals on the strip. Robustness studies showed that the annealing temperature (66 °C) was the most important condition related to reliable results. Collectively, we developed an STH-PAS method that can rapidly and easily detect rs9263726 for predicting SJS/TEN onset.

Impact of the TRPV2 Inhibitor on Advanced Heart Failure in Patients with Muscular Dystrophy: Exploratory Study of Biomarkers Related to the Efficacy of Tranilast.

Cardiomyopathy is the leading cause of death in patients with muscular dystrophy (MD). Tranilast, a widely used anti-allergic drug, has displayed inhibitory activity against the transient receptor potential cation channel subfamily V member 2 and improved cardiac function in MD patients. To identify urinary biomarkers that assess improved cardiac function after tranilast administration, we performed a urinary metabolomic study focused on oxidative fatty acids. Accompanying the clinical trial of tranilast, urine specimens were collected over 24 weeks from MD patients with advanced heart failure. Urinary levels of tetranor-PGDM (tetranor-prostaglandin D metabolite), a metabolite of prostaglandin D2, significantly decreased 12 weeks after tranilast administration and were correlated with BNP. These results suggest that prostaglandin-mediated inflammation, which increases with the pathological progression of heart failure in MD patients, was attenuated. Urinary prostaglandin E3 (PGE3) levels significantly increased 4 weeks after tranilast administration. There were positive correlations between the urinary levels of PGE3 and 8-hydroxy-2'-deoxyguanosine, an oxidative stress marker. High PGE3 levels may have a protective effect against cardiomyopathy in MD patients with high oxidative stress. Although further validation studies are necessary, urinary tetranor-PGDM and PGE3 levels may help the current understanding of the extent of advanced heart failure in patients with MD after tranilast administration.

Significant association between HLA-B*35:01 and onset of drug-induced liver injury caused by Kampo medicines in Japanese patients.

AIM: Drug-induced liver injury (DILI) is a severe and life-threatening immune-mediated adverse effect, occurring rarely among treated patients. We examined genomic biomarkers in the Japanese population that predict the onset of DILI after using a certain class of drugs, such as Kampo products (Japanese traditional medicines). METHODS: A total of 287 patients diagnosed as DILI by hepatology specialists were recruited after written informed consent was obtained. A genome-wide association analysis and human leukocyte antigen (HLA) typing in four digits were performed. RESULTS: We found a significant association (p = 9.41 × 10-10 ) of rs146644517 (G > A) with Kampo product-related DILI. As this polymorphism is located in the HLA region, we evaluated the association of HLA types and found that 12 (63.2%) of 19 Kampo-DILI patients contained HLA-B*35:01, whereas only 15.2% were positive for this HLA among healthy volunteers. The odds ratio was 9.56 (95% confidence interval 3.75-24.46; p = 2.98 × 10-6 , corrected p = 4.17 × 10-5 ), and it increased to 13.55 compared with the DILI patients not exposed to Kampo products. The individual crude drug components in the Kampo products, including Scutellaria root (ougon in Japanese), rhubarb (daiou), Gardenia fruit (sanshishi), and Glycyrrhiza (kanzou), were significantly associated with HLA-B*35:01. CONCLUSIONS: HLA-B*35:01 is a genetic risk factor and a potential predictive biomarker for Kampo-induced DILI in the Japanese population.

Iridium-catalyzed α-selective deuteration of alcohols.

The development of chemoselective C(sp3)-H deuteration is of particular interest in synthetic chemistry. We herein report the α-selective, iridium(iii)-bipyridonate-catalyzed hydrogen(H)/deuterium(D) isotope exchange of alcohols using deuterium oxide (D2O) as the primary deuterium source. This method enables the direct, chemoselective deuteration of primary and secondary alcohols under basic or neutral conditions without being affected by coordinative functional groups such as imidazole and tetrazole. Successful substrates for deuterium labelling include the pharmaceuticals losartan potassium, rapidosept, guaifenesin, and diprophylline. The deuterated losartan potassium shows higher stability towards the metabolism by CYP2C9 than the protiated analogue. Kinetic and DFT studies indicate that the direct deuteration proceeds through dehydrogenation of alcohol to the carbonyl intermediate, conversion of [IrIII-H] to [IrIII-D] with D2O, and deuteration of the carbonyl intermediate to give the α-deuterated product.

Screening and quantification of undeclared PGF2α analogs in eyelash-enhancing cosmetic serums using LC-MS/MS.

In recent years, cosmetics deemed equivalent to pharmaceutical products containing prostaglandin F2α (PGF2α) analogs have been distributed overseas in the form of eyelash serums that can be purchased via the internet. The purpose of this study was to investigate the presence or absence of PGF2α analogs in eyelash serums procured in Japan via the internet to elucidate the actual composition. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) measurement system was developed for the determination of 14 PGF2α analogs in cosmetic serums. In total, 64 eyelash serum samples were purchased from 34 websites. After pretreatment, eyelash serum samples were screened for PGF2α analogs using the LC-MS/MS system. Products containing PGF2α analogs were subjected to quantification of these compounds. Of the 64 products, four were found to contain bimatoprost, among which, three did not indicate their contents on their package labels. In contrast, no samples were found to contain latanoprost, travoprost, or tafluprost, which are prescribed for glaucoma treatment. Additionally, eight products contained other PGF2α analogs, which have not been used as pharmaceuticals. The ease of access to cosmetic serums containing PGF2α analogs via online purchases presents a risk of serious side effects, particularly when consumers are not informed of their contents on the packages. This issue requires serious consideration to avoid the incorporation of pharmaceutical substances into cosmetic products.

Impacts of SNPs on adverse events and trough concentration of imatinib in patients with gastrointestinal stromal tumors.

Although imatinib has dramatically improved the outcomes of patients with gastrointestinal stromal tumor (GIST), marked inter-individual differences in its efficacy and toxicity have been observed. Extensive pharmacogenetic studies in Caucasian and Asian populations have demonstrated that several genetic polymorphisms are involved in these differences; however, no studies have focused on Japanese patients with GIST. This study aimed to evaluate the impacts of genetic polymorphisms of drug metabolizing enzymes and transporters on the incidence of adverse events and trough plasma concentrations (Ctroughs) of imatinib in Japanese patients with GIST. Of 35 candidate SNPs genotyped from 65 patients, ABCG2 421C>A was significantly associated with increased incidence rates of grade 2 or higher rash. When relationships between the genotypes and Ctroughs were examined in a subgroup of 38 patients from whom plasma was available, 5 SNPs were associated with significant trends toward increased or decreased dose-adjusted Ctroughs. Of them, SLCO1B3 334T>G and SLCO1A2 -1032G>A made significant contributions to the individual variability of Ctrough by multivariate regression analysis. Genetic variations in ABCG2, SLCO1B3, and SLCO1A2 may play important roles in the safety and pharmacokinetics of imatinib in Japanese patients with GIST, although a replication study is necessary for validation.

Structure of Cytochrome P450 2C9*2 in Complex with Losartan: Insights into the Effect of Genetic Polymorphism.

The human CYP2C9 plays a crucial role in the metabolic clearance of a wide range of clinical therapeutics. The *2 allele is a prevalent genetic variation in CYP2C9 that is found in various populations. A marked reduction of catalytic activity toward many important drug substrates has been demonstrated by CYP2C9*2, which represents an amino acid variation at position 144 from arginine to cysteine. The crystal structure of CYP2C9*2 in complex with an antihypertensive drug losartan was solved using X-ray crystallography at 3.1-Å resolution. The Arg144Cys variation in the *2 complex disrupts the hydrogen-bonding interactions that were observed between the side chain of arginine and neighboring residues in the losartan complex of CYP2C9 and the wild-type (WT) ligand-free structure. The conformation of several secondary structural elements is affected, thereby altering the binding and orientation of drug and important amino acid side chains in the distal active site cavity. The new structure revealed distinct interactions of losartan in the compact active site of CYP2C9*2 and differed in occupancy at the other binding sites previously identified in the WT-losartan complex. Furthermore, the binding studies in solution using losartan illustrated lower activity of the CYP2C9*2 compared with the WT. Together, the findings yield valuable insights into the decreased hydroxylation activity of losartan in patients carrying CYP2C9*2 allele and provide a useful framework to investigate the effect of a single-nucleotide polymorphism that leads to altered metabolism of diverse drug substrates. SIGNIFICANCE STATEMENT: The *2 allele of the human drug-metabolizing enzyme CYP2C9 is found in different populations and results in significantly reduced activity toward various drug substrates. How the CYP2C9*2 variant induces altered drug metabolism is poorly understood given that the Arg144Cys variation is located far away from the active site. This work yield insight into the effect of distal variation using multitude of techniques that include X-ray crystallography, isothermal titration calorimetry, enzymatic characterization, and computational studies.

Hepatic Adaptation to Therapeutic Doses of Acetaminophen: An Exploratory Study in Healthy Individuals.

PURPOSE: Acetaminophen (APAP) has hepatotoxic potential when overdosed. Recent studies have reported serum alanine aminotransferase (ALT) elevations that resolve spontaneously with continued use of the drug, referred to as adaptation, in several individuals receiving therapeutic doses of APAP. However, the clinical significance of these ALT elevations remains unclear. This study was performed to investigate the incidence and characteristics of hepatic adaptation to therapeutic doses of APAP in healthy individuals. METHODS: In a randomized, single-blind, placebo-controlled study, 242 healthy Japanese individuals were enrolled. Each person received 3 g/d of APAP (n = 202) or placebo (n = 40) for 28 days. All study participants underwent analysis of genetic polymorphisms of CYP2E1 and UGT1A1; measurements of plasma APAP concentration and urine metabolites (glucuronide, sulfate, cysteine, and mercapturate); liver function monitoring, including ALT, microRNA-122, and high-mobility group box 1. Individuals with ALT levels remaining below the upper limit of normal (ULN; 40 U/L) during the study period were defined as tolerant and those with ALT elevations above the ULN as susceptible. Susceptible individuals who developed ALT elevations exceeding 2 × ULN discontinued use of the study drug for tolerability consideration. Susceptible individuals who had ALT elevations that decreased toward the ULN spontaneously with continued use of the study drug were classified as adaptation. FINDINGS: In the APAP group, 129 individuals (66%) were classified as tolerant and 65 (34%) as susceptible. Among 65 susceptible individuals, 12 (18%) discontinued use of APAP because of ALT elevations (>2 × ULN), whereas 53 (82%) completed 28-day APAP dosing. Thirty of 65 susceptible individuals (46%) had adaptation within 28 days. In the placebo group, no individuals was withdrawn from the study because of elevated ALT levels, 33 individuals (89%) were classified as tolerant, and 4 (11%) were classified as susceptible. None had clinical signs of liver injury. ALT level correlated significantly with microRNA-122 but not with high-mobility group box 1. No association was found between plasma APAP concentrations and ALT levels. Urinary excretion of APAP mercapturate was higher in susceptible than in tolerant individuals (P = 0.018, Wilcoxon or Kruskal-Wallis test). The frequency of homozygotes and compound heterozygotes for UGT1A1∗28 and UGT1A1∗6 (∗28/∗28, ∗6/∗6, and ∗6/∗28) was higher in susceptible than in tolerant individuals (13.9% vs 3.9%; P = 0.011, χ2 test). IMPLICATIONS: These findings indicate that in healthy individuals, APAP at a therapeutic dose can cause transient and self-limiting ALT elevation, reflecting subclinical hepatocellular damage, and these ALT elevations may be associated with the disposition of APAP metabolites and genetic factors. UMIN-CTR identifier: UMIN000019607.

Clinical study designs and patient selection methods based on genomic biomarkers: Points-to-consider documents.

Recently, genomic biomarkers have been widely used clinically for prediction of the efficacy and safety of pharmacotherapy and diagnosis and prognosis of pathological conditions. Therefore, genomic biomarkers are anticipated to accelerate not only precision medicine for pharmacotherapy but also development of molecularly targeted drugs. Because the design of clinical studies involving biomarkers may differ from conventional clinical study designs, a concept paper focused on clinical studies and patient selection methods based on genomic biomarkers is desired to prompt innovative drug development. Thus, this concept paper aimed to compile and present current scientific information from the related guidelines regarding application of genomic biomarkers to clinical trials and studies for drug development. We hope that this concept paper will prompt the development of guidelines for biomarker application to drug development by industry, regulatory authorities, the medical profession, and academia.

Lipidomic signatures of aortic media from patients with atherosclerotic and nonatherosclerotic aneurysms.

Aortic aneurysms are associated with fatal aortic rupture. Current therapeutic approaches are limited to implantation of aortic prostheses and stent-grafts; no effective drugs are available because the pathogenic mechanisms of aortic aneurysms remain unclear. Here, we aimed to elucidate the molecular mechanisms of the initiation and progression of aortic aneurysm by lipidomics. We performed lipidomics analyses of lipids in the aortic media of normal, border, and aneurysm areas from patients with thoracic atherosclerotic aortic aneurysm (N = 30), thoracic nonatherosclerotic aortic aneurysm (N = 19), and abdominal atherosclerotic aortic aneurysm (N = 11) and from controls (N = 8) using liquid chromatography and mass spectrometry. Significant alterations were observed in the lipid profiles of patients with atherosclerotic aortic aneurysms and to a lesser extent in those with nonatherosclerotic aneurysms. Increased triacylglycerols (TGs) and decreased ether-type phosphatidylethanolamines (ePEs) were observed throughout the normal, border, and aneurysm areas of thoracic and abdominal atherosclerotic aortic aneurysms. Prostaglandin D2 increased, but ePEs and TGs decreased in normal areas of thoracic atherosclerotic aortic aneurysms and thoracic nonatherosclerotic aortic aneurysms compared with the control tissues. These findings expand our knowledge of metabolic changes in aortic aneurysms and provide insights into the pathophysiology of aortic aneurysms.

Serum lipidomics for exploring biomarkers of bortezomib therapy in patients with multiple myeloma.

Although the proteasome inhibitor bortezomib (BTZ) shows excellent efficacy in multiple myeloma (MM), a fraction of patients has a suboptimal or no response to this agent. In addition, BTZ-induced peripheral neuropathy (BiPN), a frequent side-effect of this therapy, limits its use in some patients. This study aimed to explore serum lipid biomarker candidates to predict the response to BTZ and the severity of BiPN. Fifty-nine serum samples were collected from patients with MM prior to receiving BTZ plus low-dose dexamethasone therapy. Serum levels of phospholipids, sphingolipids, neutral lipids, and polyunsaturated fatty acids and their oxidation products were measured by a comprehensive lipidomic study. Overall, 385 lipid metabolites were identified in patients' sera; lower levels of several glycerophospholipids, sphingolipids, and cholesteryl esters were associated with a poor treatment response. Metabolites related to platelet-activating factor biosynthesis and cholesterol metabolism appeared particularly relevant. Furthermore, several lysophosphatidylcholines, phosphatidylcholines, ceramides, neutral lipids, and oxidative fatty acids were significantly increased or decreased in patients with BiPN grades ranging from G0 to G3. Among these compounds, mediators reportedly inducing myelin breakdown and stimulating inflammatory responses were prominent. Although further study is necessary to validate these biomarker candidates, our results contribute to the development of predictive biomarkers for response to BTZ treatment, or ensuing severe BiPN, in patients with MM.

Structural Basis of Single-Nucleotide Polymorphisms in Cytochrome P450 2C9.

Single-nucleotide polymorphisms in drug-metabolizing cytochrome P450 (CYP) enzymes are important contributors to interindividual differences in drug metabolism leading to adverse drug reactions. Despite their extensive characterization and importance in pharmacogenetics of clinical drugs, the structural basis of CYP polymorphisms has remained scant. Here we report the crystal structures of human CYP2C9 and its polymorphic variants, *3 (I359L) and *30 (A477T), with an antihypertensive drug losartan. The structures show distinct interaction and occupation of losartan in the active site, the access channel, and the peripheral binding site. The I359L substitution located far from the active site remarkably altered the residue side chains near the active site and the access channel, whereas the T477 substitution illustrated hydrogen-bonding interaction with the reoriented side chain of Q214. The results yield structural insights into the reduced catalytic activity of the CYP2C9 variants and have important implications for understanding genetic polymorphisms in CYP-mediated drug metabolism.

Plasma Lipidomics of Healthy Japanese Adults Reveals Gender- and Age-Related Differences.

Lipid metabolites in the blood are expected to be biomarker candidates to reflect disease states and responses to therapeutic drugs. However, their profiles are influenced by subject background, which may lead to confounding results. This study aimed to evaluate whether age and gender affect lipid metabolite levels in the plasma of healthy Japanese adults. Comprehensive lipidomic analysis was performed using liquid chromatography-mass spectrometry for overnight fasted volunteers consisting of 4 groups of 15 subjects each: young males (25-35 years), elderly males (55-64 years), young females (25-35 years), and elderly females (55-65 years). Of 326 detected lipids, none showed significant gender-associated differences in the young groups and 3 metabolites showed significant gender-associated differences in the elderly groups, suggesting that age has little impact on plasma lipid levels in Japanese subjects. We found age-associated differences in 111 (34%) and 115 (35%) metabolites in males and females, respectively, indicating that the subjects' age should be considered an important confounding factor for lipid biomarker exploration and validation studies in Japanese populations. These findings provide fundamental information on biomarker discovery, validation, and qualification processes in Japanese populations, and facilitate the evaluation of biomarker candidates found in other populations.

Evaluation of the Potential Risk of Drugs to Induce Hepatotoxicity in Human-Relationships between Hepatic Steatosis Observed in Non-Clinical Toxicity Study and Hepatotoxicity in Humans.

In the development of drugs, we sometimes encounter fatty change of the hepatocytes (steatosis) which is not accompanied by degenerative change in the liver in non-clinical toxicity studies. In this study, we investigated the relationships between fatty change of the hepatocytes noted in non-clinical toxicity studies of compound X, a candidate compound in drug development, and mitochondrial dysfunction in order to estimate the potential risk of the compound to induce drug-induced liver injury (DILI) in humans. We conducted in vivo and in vitro exploratory studies for this purpose. In vivo lipidomics analysis was conducted to investigate the relationships between alteration of the hepatic lipids and mitochondrial dysfunction. In the liver of rats treated with compound X, triglycerides containing long-chain fatty acids, which are the main energy source of the mitochondria, accumulated. Accumulation of these triglycerides was considered to be related to the inhibition of mitochondrial respiration based on the results of in vitro mitochondria toxicity studies. In conclusion, fatty change of the hepatocytes (steatosis) in non-clinical toxicity studies of drug candidates can be regarded as a critical finding for the estimation of their potential risk to induce DILI in humans when the fatty change is induced by mitochondrial dysfunction.

Cross-Classification of Human Urinary Lipidome by Sex, Age, and Body Mass Index.

Technological advancements in past decades have led to the development of integrative analytical approaches to lipidomics, such as liquid chromatography-mass spectrometry (LC/MS), and information about biogenic lipids is rapidly accumulating. Although several cohort-based studies have been conducted on the composition of urinary lipidome, the data on urinary lipids cross-classified by sex, age, and body mass index (BMI) are insufficient to screen for various abnormalities. To promote the development of urinary lipid metabolome-based diagnostic assay, we analyzed 60 urine samples from healthy white adults (young (c.a., 30 years) and old (c.a., 60 years) men/women) using LC/MS. Women had a higher urinary concentration of omega-3 12-lipoxygenase (LOX)-generated oxylipins with anti-inflammatory activity compared to men. In addition, young women showed increased abundance of poly-unsaturated fatty acids (PUFAs) and cytochrome P450 (P450)-produced oxylipins with anti-hypertensive activity compared with young men, whereas elderly women exhibited higher concentration of 5-LOX-generated anti-inflammatory oxylipins than elderly men. There were no significant differences in urinary oxylipin levels between young and old subjects or between subjects with low and high BMI. Our findings suggest that sex, but neither ages nor BMI could be a confounding factor for measuring the composition of urinary lipid metabolites in the healthy population. The information showed contribute to the development of reliable biomarker findings from urine.

A possible role for HLA-DRB1*04:06 in statin-related myopathy in Japanese patients.

Statin-related myopathy (SRM) is a clinically important adverse reaction. Recent pharmacogenetic research, mainly in non-Asian populations, have indicated clinical relevance of some of genetic biomarkers to SRM, but predictive markers for SRM in Asian populations including Japanese has not yet been established. This study was aimed to identify clinically important genetic markers associated with SRM in Japanese patients. Allele frequencies of the three reported candidate markers - SLCO1B1 rs4149056, RYR2 rs2819742, and GATM rs9806699 - and carrier frequencies of HLA types were compared between patients with SRM patients (n = 52) and healthy Japanese subjects (n = 2878 or 86 (for rs9806699) as controls). No significant association of RYR2, SLCO1B1, and GATM variants with SRM were observed in our Japanese patients, but a significant association was detected for HLA-DRB1*04:06 with SRM (odds ratio: 3.19; 95% confidence interval: 1.53-6.66). This study suggested that HLA-DRB1*04:06 might be associated with SRM onset in a Japanese population. Further studies are required to validate these results.

Plasma Lipid Profiling of Patients with Chronic Ocular Complications Caused by Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis.

Stevens-Johnson syndrome (SJS) and its severe variant, toxic epidermal necrolysis (TEN), are drug-induced acute inflammatory vesiculobullous reactions of the skin and mucous membranes, including the ocular surface. Even after recovery from skin symptoms, some SJS/TEN patients continue to suffer with severe ocular complications (SOCs). Therefore, this study aims to understand the pathophysiology of chronic SOCs. Because plasma lipid profiling has emerged as a useful tool to understand pathophysiological alterations in the body, we performed plasma lipid profiling of 17 patients who suffered from SJS/TEN-associated chronic SOCs. A lipidomics approach yielded 386 lipid molecules and demonstrated that plasma levels of inflammatory oxylipins increased in patients with SJS/TEN-associated chronic SOCs. In addition, oxidized phosphatidylcholines and ether-type diacylglycerols increased in the patients with chronic SOCs, while phosphoglycerolipids decreased. When we compared these lipidomic profiles with those of patients with atopic dermatitis, we found that patients with chronic SOCs, specifically, had decreased levels of ether-type phosphatidylcholines (ePCs) containing arachidonic acid (AA), such as PC(18:0e/20:4) and PC(20:0e/20:4). To confirm our finding, we recruited additional patients, who suffered from SOC associated with SJS/TEN (up to 51 patients), and validated the decreased plasma levels of AA-containing ePCs. Our study provides insight into the alterations of plasma lipidomic profiles in chronic SOCs and into the pathophysiology of SJS/TEN-associated chronic SOCs.